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Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya
Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya S. Sujatha a,⇑, R. Sivarethinamohan b a b
Department of Civil Engineering, K. Ramakrishnan College of Technology, Tiruchirappalli, Tamil Nadu, India Christ University, Bengaluru, Karnataka 560029, India
a r t i c l e
i n f o
Article history: Received 11 June 2019 Accepted 28 June 2019 Available online xxxx Keywords: Activated carbon FTIR Heavy metal SEM XRD
a b s t r a c t Heavy metals are poisonous and detrimental water contaminant. Their existence affects human beings, animals and vegetation as a outcome of their mobility in aqueous ecosystem, toxicity and nonbiodegradability. This work aimed at the development of new adsorbent in the detoxification of heavy metals using Manilkara zapota tree wood and de oiled soya. The study completely focused on the characterization of the developed activation in the view of using it as a adsorbent. The characterization of activated carbon was effected SEM analysis, FTIR, XRD analysis and surface area determination. Both the activation carbon have showed a tremendous characterization in their employability as adsorbent in adsorption of heavy metals in aqueous solution. Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
1. Introduction Accelerated growth of human population and increasing technological innovation have spoiled the environment to a great level during the few years [1]. Unjustifiable utilization of natural resource and extreme use of toxic natured material might put in danger the very survival of life on this earth and evident environmental intervention intimidating the life maintain structure. The occurrence of components like toxic heavy metal ions or relentless organic pollutants might produce terrible effects on the ecosystems where they are released into. Heavy metals are normally stated to as those metals which have a specific density of more than 5 g/cm3 [2] which badly affect the environment and living organisms [3]. The release of domestic and industrial effluents and other man-made activities have arised in high levels of heavy metals accumulation in drinking water sources [4]. Amongst diverse metal ions, divalent lead and hexavalent chromium are most normally present in the environment and very harmful to human and ecosystem too. Therefore, it is requisite to treat metal infected wastewater before its set free into the environment. It initiates research at the core level to guard the environment from metal waste toxicity. As per USEPA (U.S. Environment Protection Agency) the divalent lead concentration must be below the level of 15 parts ⇑ Corresponding author. E-mail address: [email protected] (S. Sujatha).
per billion for drinking water and hexavalent chromium concentration 100 parts per billion for drinking water [4,5]. For wastewaters the concentration of both metals is 0.1 mg/l, given by both USEPA and Bureau of Indian Standards (BIS) [4,6]. Heavy metal elimination from industrial effluents can be done by conservative treatment techniques like chemical precipitation [7], coagulation, complexation, ion exchange [8], adsorption by activated carbon [Peters1985. Nevertheless, adsorption process is competent and eco-friendly technique particularly for the exclusion of heavy metal ions from aqueous solution. In this study, activated carbon were fabricated from citric acid treated Manilkara zapota tree wood and from de-oiled soya independently and their material characterization like presence of functional groups and surface morphology were evaluated with Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analysis to find the suitability to act as s adsorbent in the adsorption of divalent lead and hexavalent chromium.
1.1. Lead toxicity Lead is widely used in the industries similar to battery manufacturing, pigments, fuels, photographic materials, explosive manufacturing and printing. Spotlight to lead is highly inclined to health damages for children and adults as well [8,9]. Equally, calcium present in bone is replaced by lead.
https://doi.org/10.1016/j.matpr.2019.06.735 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
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1.2. Chromium toxicity Environmental pollution payable to chromium is most perceptible in leather manufacturing [10] electroplating [11], electronic manufacturing and other metal based operations. The carcinogenic and mutagenic character of hexavalent chromium [12,13] create ecological damage and health problems to mankind. 2. Materials and methods 2.1. Adsorbent Adsorbent is a solid substance that has a ability to adsorb another matter. Significant types of adsorbents in live out are silica gel, activated carbon, molecular sieve carbon, molecular sieve zeolites, activated alumina, and polymeric adsorbents. Many adsorbents are man-made (such as activated carbons), but a minimal adsorbents like zeolites, occur naturally. Every material has its own characteristics such as porosity, pore structure and nature of its adsorbing surfaces. 2.2. Adsorbate The matter which is being adsorbed on the surface of another matter is termed as adsorbate. Effluents such as heavy metals, dyes which have the ability to be adsorbed by the adsorbent are named as adsorbate. In common those matters which are to be abolished greatly from the atmosphere are coming under the category of adsorbate. 2.3. Activated carbon Activated is a porous, amorphous solid encircling of micro crystallites with a graphite lattice. Adsorption capacity is correlated to the surface morphology and chemical nature of the carbon surface in alliance with preparation conditions. So the present paper deeds to study the viability of using activated carbon developed from Manilkara zapota tree wood and de oiled soya. 2.4. Precursors used in the development of activated carbon Manilkara Zapota tree wood and de oiled soya were the two precursors used for the production of activated carbons.
the waste product which is received after the extraction of the oil is termed as de oiled soya. De oiled soya was collected from a private industry in Tamilnadu. 2.5. Preparation of activated carbon The present study intended to set up a new activated carbons developed from Manilkara zapota tree wood and de oiled soya independently. 2.5.1. Preparation of activated carbon of Manilkara zapota tree wood The preparation procedure involved the following stages a) Manilkara zapota tree wood was ground into small pieces and washed with distilled water to remove foreign materials. b) The materials obtained were heated in an oven at a temperature of 70° C for 4 to 5 h till it was completely dehydrated c) The dried ground wood was washed again with 0.1 N NAOH solutions thoroughly and stirred at 200 rpm for 60 min to remove the excess base from the wood. d) The resultant bio-mass was immersed in the citric acid for 5 h. Thereafter it was dried in oven for 3 h at a temperature of 105° c followed by burning process in a muffle furnace at 500° c for 3 h. e) The tree based carbon obtained was again kept in an oven at a temperature of 105° c for an hour for the accomplishment of carbon activation procedure. f) Manual crushing of the activated carbon was carried out to reduce the size of the carbon. g) The carbon that conceded in 150m sieve and hung in 90m sieve was stored in an airtight container. Manilkara zapota tree wood pieces were displayed in Figs. 1 and 2 indicated the activated carbon of it. 2.5.2. Preparation of activated carbon of de oiled soya The procedure concerned the following stages. 1. The development of the adsorbent was made by first grinding the de oiled soya into small pieces and washing with distilled water and drying in an oven till it was dehydrated.
2.4.1. Manilkara Zapota tree wood Manilkara Zapota tree across the world is well-known as the sapodilla tree, is a long-lived, evergreen tree native to southern mexico, central america and the caribbean. It produces a sweet, luscious fruit sapota. It is a drought-resistant and wind-resistant tree. Sapodilla can grow over 30 m (98 ft) tall with an average trunk diameter of 1.5 m (4.9 ft) and being a deep rooted and drought-resistant crop has been found to be an ideal plant for two tier cropping system with chilies as an intercrop in dry areas. India is the largest producer of sapota followed by Mexico, Guatemala and Venezuela. India has 162 thousand hectares of land under cultivation of sapota and produces about 1358 thousand tones of sapota per year. In Tamilnadu, it has become a very popular fruit crop in Dindigul, Coimbatore, Virudhunagar, Theni and Namakkal. 2.4.2. De oiled soya Another precursor, de oiled soya is derived from a bean called glycine max, commonly known as soya bean. It is a legume species native of East Asia which is widely grown for its bean which is edible in nature. Soya oil is prepared by crushing the soya bean and
Fig. 1. Zapota tree wood.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
S. Sujatha, R. Sivarethinamohan / Materials Today: Proceedings xxx (xxxx) xxx
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Fig. 4. Activated carbon of de oiled soya. Fig. 2. Activated carbon of manilkara zapota tree wood.
2. In order to oxidize the impurities the dried de oiled soya was then treated with hydrogen peroxide solution (30% w/v) at room temperature for about 24 h [14]. 3. The resultant material was washed with distilled water. the hydrogen-peroxide treated adsorbent was positioned in an oven at 100°c by which the moisture was removed. 4. Furthermore, it was kept in a muffle furnace at 350°c temperature for a time period of 3 h. 5. The obtained carbon was reduced in size by crushing the same. yet again it was set aside in a muffle furnace at 200°c for 1 h for activation process. 6. The carbon was subsequently sieved into two mesh sizes is 150m and 90-m sieves. 7. Carbon that was retained in the 90-m sieve and passing through the 150-m sieve was stored in an airtight container for further experiments.
(SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons ZEISS EVO-18 scanning electron microscopic instrument was employed in the present study to capture the SEM images of ACs of Manilkara Zapota and de oiled soya before and after adsorption.
2.7. Fourier transform infrared (FTIR) spectroscopic analysis
2.6. Scanning electron Microscopic (SEM) analysis
FTIR is a rapid, nondestructive, time saving method that can detect a range of functional groups in sample and used to characterize the functional groups responsible for heavy metal adsorption [16,17]. The functional groups responsible for adsorption of chromium (VI) and lead (II) metal ions of ACs of de oiled soya and Manilkara zapota tree wood were investigated by FTIR analysis. The frequency ranges are measured as wave numbers typically over the range 4000–400 cm 1. Infrared spectroscopic technique is conducted in an instrument called an infrared spectrometer (or spectrophotometer). Fourier transform infrared spectroscopy Perkin Elmer make – model spectrum RX1 (Range 4000–400 cm 1) was employed to obtain the FTIR spectrum of the adsorbents in the current study.
The SEM technique provides information on the association of metals in an adsorbent [15]. A Scanning Electron Microscope
2.8. X-Ray Fluorescence (XRF) Elemental analysis
De oiled soya was displayed in Figs. 3 and 4 revealed the activated carbon of it.
XRF analytical microscope determines the chemistry of a sample by measuring the emitted fluorescent X-ray from a sample. The sample is excited by a primary source to produce X-ray which is a secondary source from the sample. Presence of various elements in the activated carbons developed from Manilkara zapota and de oiled soya were determined by using XGT-2700 X-ray analytical microscope.
2.9. X-Ray Diffraction (XRD) Elemental analysis
Fig. 3. De oiled soya.
X-ray diffraction (XRD analysis or XRPD analysis) is a unique method in determination of crystallinity of a compound. The characteristic x-ray diffraction pattern generated in a typical XRD analysis provides a unique ‘‘fingerprint” of the crystals present in the sample. The adsorbents developed in this research were undergone analysis in X-ray X-Pert pro panalytical instrument.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
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2.10. Brunauer-Emmett-Teller (BET) analysis Gas adsorption analyzer with Brunauer-Emmett-Teller (BET) method was exercised in the present study for the surface area determination where N2 gas was used as adsorbate. It serves as the measurement of the specific surface area of materials. 3. Results and discussion 3.1. Scanning Electron Microscopic (SEM) analysis Surface morphological images of AC of Manilkara zapota tree wood and de oiled soya were exhibited in Figs. 5 and 6. SEM images of both the ACs revealed the existence of irregular and porous surface which could facilitate the adsorption of metal ions on different pores of the adsorbent. A good deal of space was visible in both adsorbents which would be more beneficial for the adsorption process to occur on the surface of the carbon. Both the adsorbents had rough texture with heterogeneous surface and a variety of randomly distributed pore size which is a characteristic of a potential adsorbent. A rough surface and abundant pores would provide suitable diffusion passages for ions onto the carbons [18].
Fig. 6. SEM image of AC developed from de oiled soya.
3.2. Fourier Transform Infrared Spectroscopic analysis (FTIR) and Brunauer–Emmett–Teller (BET) surface area analysis From the Fig. 7 it could be clearly known that AC prepared from Manilkara zapota possessed a broad peak at 3433.06 cm 1 [21,19,20] could be allotted to AOH stretch from hydroxyl to phenolic groups. Similarly the peaks appeared at 2937.2 cm 1 and 1421.18 cm 1 were attributed to CAH stretching of aliphatic acids [19]. In this AC the peaks from 1299.46 cm 1 to 1046.03 cm 1 were endorsed to CAO stretching of alcohols [19,21]. Further the peak with wavelength 1115.08 cm 1 [22]possessed the functional group CAO stretching of carboxylic acid and alcohols in the adsorbent. Likewise the peaks located in between 926.07 cm 1 and 816.14 cm 1 were authorized to CAH aromatic rings [22]. It was observed from Fig. 8, that the FTIR spectrum of the AC prepared from de oiled soya was consisting of peak at 3339 cm 1 [19,20] could be attributed to AOH (hydroxyl) groups. The peaks 2870.49 cm 1 and 2926.49 cm 1 indicated the presence of CAH stretch of aliphatic [19] acids in AC. It further revealed peaks at 1651.14 cm 1 related to C@C [23] stretch alkenes. The Peak 1603.55 cm 1 referred to C@O (carbonyl group)stretch aromatic
Fig. 7. FTIR spectrum of AC developed from Manilkara zapota.
Fig. 8. FTIR spectrum of AC developed from de oiled soya.
Fig. 5. SEM image of AC developed from Manilkara zapota.
groups like primary and secondary amides [21,22]. The peaks 1113.06 cm 1 and 1161.17 cm 1 [22] exhibited the existence of CAO stretching of alcohols, and carboxylic acid in the adsorbent.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
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Furthermore the peaks between 700.73 cm 1 and 753.80 cm 1 could be assigned to CAH aromatic rings [22,24]. The surface area was found to be 24.47 m2/g for de-oiled soya activated carbon and surface area was found to be 29.12 m2/g for Manilkara zapota tree wood based activated carbon. These surface areas had a good deal in favoring the adsorption process. 3.3. X-Ray Fluorescence (XRF) elemental analysis From Table 1 it was clear that seven heavy metals such as Si, K, Ca, Ti, Fe, Cu and O were found in activated carbon of Manilkara zapota. Among these, K, Ca and O were concentrated on 85.934% of weight. On the other hand seven heavy metals such as Si, K, Ca, Ti, Mn and Fe were found in activated carbon of de oiled soya. Among these, K and Ca were identified as key elements and they were concentrated on 83.17% of weight. The order of elements in activated carbon of Manilkara zapota is O > Ca > K > Si > Fe > Ti > Cu
Fig. 9. XRD spectrum of AC of Manilkara zapota.
The order of elements in activated carbon of de oiled soya is K > Ca > Si > Ti > Mn > Fe It was pragmatic from the Table 1 that activated carbon of Manilkara zapota had no manganese content but has high calcium ion content of 28.939% and several other metals. Whereas activated carbon of de oiled soya had low manganese content but had high potassium and calcium ions content of 55.43% and 27.74% respectively. Transition metals like Cu, Mn, Fe and Ti were present in the ACs which could be act as catalyst during adsorption process. 3.4. X-Ray Diffraction (XRD) analysis Fingerprint of the ACs were attributed to the peak intensities exhibited in the Figs. 9 and 10. This was by the distribution of atoms within the ACs lattice. In the spectrum very less number of peaks were observed which showed that the developed carbons were amorphous in nature. The peaks observed in XRD patterns 2h = 25°and 48° in both the carbon samples were due to the existence of Faujasite and Sodium Silicates [25] respectively. In addition to it AC of Manilkara zapota had peaks 2h = 29° and 31° were due to the presence of Zeolite and Mullite [25]. 4. Conclusion SEM analysis exposed the presence of irregular and porous surface which could smooth the progress of the adsorption of metal ions on different pores of the the developed activated carbon of Manailkara zapota and de oiled soya are. The FTIR spectrum
Fig. 10. XRD spectrum of AC of de oiled soya.
potrayed that the carbons have hydroxyl, carboxy and amine groups which have a greater affinity towards the heavy metal ion. Less number of peaks in XRD spectrum were observed which illustrated that the developed carbons were amorphous in nature. It could be concluded that the activated carbon produced from Manilkara zapota and from de oiled soya independently showed a tremendous charecterisation which can be better used as a adsorbent in adsorption process of detoxifying the heavy metal contaminated water.
Table 1 Elemental composition of activated carbons as revealed by XRF. Adsorbent elements
AC of Manilkara zapota % by weight
AC de oiled soya % by weight
Si K Ca Ti Fe Cu O Mn Total
7.464 27.791 28.939 2.987 3.133 0.482 29.204 – 100
9.77 55.43 27.74 1.11 5.36 – – 0.59 100
References [1] Indur M Goklany, ‘Have increases in population, affluence and technology worsened human and environmental well-being?, Electron J. Sustain. Dev. 1 (3) (2009) 3–28. [2] A.B. Duwiejuah, S.J. Cobbina, N. Bakobie, Review of eco-friendly biochar used in the removal of trace metals on aqueous phases, Int. J. Environ. Bioremed. Biodegr. 5 (2) (2017) 27–40. [3] Lars Jarup, Hazards of metal contamination, British. Medical Bulletin, The British council, vol. 68, 2003, pp. 167–182. [4] R. Vinodhini, M. Narayanan, Bioaccumulation of heavy metals in organs of fresh water fish Cyprinus carpio (common carp), Int. J. Environ. Sci. Technol. 5 (2) (2008) 179–182.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
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[5] Ebtesam El-Bestawy, Majdah Abu Rass, Mervat Amin Abdel-Kawi, Removal of lead and oil hydrocarbon from oil refining-contaminated wastewater using Pseudomonas spp, J. Natl. Sci. Res. 3 (11) (2013) 112–124. [6] Sumeth Khaoya, Ura Pancharoen, Removal of lead (II) from battery industry wastewater by HFSLM, Int. J. Chem. Eng. Appl. 3 (2) (2012) 99–103. [7] M. Wiemann, K. Schirrmacher, D. Busselberg, Interference of lead with the calcium release activated calcium flux of osteoblast-like cells’, Calcif. Tissue Int. 65 (1999) 479–485. [8] Lovell Agwaramgbo, Nancy Magee, ShaKayla Nunez, Kayla Mitt, Biosorption and chemical precipitation of lead using biomaterials, molecular sieves, and chlorides, carbonates, and sulfate Na & Ca, J. Environ. Prot. 4 (2013) 1251– 1257. [9] Philip J. Landrigan, Clyde B. Schechter, Jeffrey M. Lipton, Marianne C. Fahs, Joel Schwartz, Environmental pollutants and disease in American children: estimates of morbidity, mortality, and costs for lead poisoning, asthma, cancer, and developmental disabilities, Environ. Health Perspect. 11 (7) (2002) 721–728. [10] Sadia R. Tariq, Munir H. Shah, N. Shaheen, A. Khalique, S. Manzoor, M. Jaffar, Multivariate analysis of trace metal levels in tannery effluent in relation to soil and water: a case study from Peshawar, Pakistan, J. Environ. Manage. 79 (2006) 20–29. [11] Siddiqa Tufail Mughal, Tahira Shafique, Tayyaba Aftab, Farzana Bashir, Treatment of electro plating effluen, J. Chem. Soc. Pakistan 30 (1) (2008) 29– 32. [12] Tor Norseth, The carcinogenicity of chromium, Environ. Health Perspect. 40 (1981) 121–130. [13] S. Sujatha, G. Venkatesan, R. Sivarethinamohan, Principal determinants of toxicity reduction by de-oiled soya using multivariate statistics: principal component analysis and multiple linear regression analysis, Appl. Ecol. Environ. Res. 15 (3) (2017) 1717–1737. [14] Alok Mittal, Damodar Jhare, Jyoti Mittal, Adsorption of hazardous dye Eosin Yellow from aqueous solution onto waste material De-Oiled Soya: isotherm, kinetics and bulk removal, J. Mol. Liq. 179 (2013) 133–140. [15] Young-Hoon Jo, Si-Hyun Do, Yoon-Seok Jang & Sung-Ho Kong, The removal of metal ions (Cu2+ and Zn2+) using waste-reclaimed adsorbent for plating
[16]
[17]
[18] [19]
[20]
[21]
[22]
[23]
[24]
[25]
wastewater treatment process, in: Proceedings of the World Congress on Engineering and Computer Science(WCECS 2010),San Francisco, USA, 2010. Florina Csernatoni, Carmen Socaciu, Raluca Maria Pop, Florinela Fetea, Florina Bunghez, Application of FT-IR spectroscopy for fingerprinting bioactive molecules in a nutraceutical PROMEN, comparatively with plant ingredients, J. Food Sci. Technol. 70 (1) (2013) 68–69. Sahira Joshi & Bhadra Prasad Pokharel, preparation and characterization of activated carbon from lapsi (Choerospondias axillaris) seed stone by chemical activation with potassium hydroxide, J. Inst. Eng. 9 (1) (2012) 79–88. Dongmei Jia, Changhai Li, Adsorption of Pb (II) from aqueous solutions using corn straw, Desalination Water Treat. (2014) 1–9. Sarifah Fauziah Syed Draman, Norzila Mohd, Nor Hafiza Izzati Wahab, Nurul Syahirah Zulkfli, Nor Fatin Adila Abu Bakar, Adsorption of lead (II) ions in aqueous solution using selected agro-waste, ARPN J. Eng. Appl. Sci. 10 (1) (2015) 297–300. Ting Wang, Weican Zhang, Lu. Xuemei, ‘Preparation Cu (II) adsorption characteristics of carboxymethyl cross-linked sewage sludge, Pol. J. Environ. Stud. 25 (2) (2016) 805–811. Ch. Suresh, Y. Harinath, B. Ramesh Naik, K. Seshaiah, Removal of Pb (II) from aqueous solution by critic acid modified Manilkara zapota leaves powder: equilibrium and kinetic studies, J. Chem. Pharmuetical Res. 7 (4) (2015) 1161– 1174. Parag A. Pednekar, Bhanu Raman, The FT-IR spectrometric studies of vibrational bands of Semecarpus anacardium Linn. F. leaf, stem powder and extracts, Asian J. Phamaceutical Clin. Res. 6 (1) (2013) 159–168. Macharia A. Njoki, Githua Mercy, Gathu Nyagah, Anthony Gachanja, Fourier transform infrared spectrophotometric analysis of functional groups found in Ricinus communis L. and Cucurbita maxima lam. roots, stems and leaves as heavy metal adsorbents, Int. J. Sci. Environ. Technol. 5 (3) (2016) 861–871. M.N. Younis, M.S. Saeed, S. Khan, M.U. Furqan, R.U. Khan, M. Saleem, Production and characterization of biodiesel from waste and vegetable oils, J. Qualityand Technol. Manage. V (1) (2009) 111–121. Z. Al-Qodah, R. Shawabkah, Production and characterization of granular activated carbon from activated sludge, Braz. J. Chem. Eng. 26 (1) (2009) 127– 136.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya S. Sujatha a,⇑, R. Sivarethinamohan b a b
Department of Civil Engineering, K. Ramakrishnan College of Technology, Tiruchirappalli, Tamil Nadu, India Christ University, Bengaluru, Karnataka 560029, India
a r t i c l e
i n f o
Article history: Received 11 June 2019 Accepted 28 June 2019 Available online xxxx Keywords: Activated carbon FTIR Heavy metal SEM XRD
a b s t r a c t Heavy metals are poisonous and detrimental water contaminant. Their existence affects human beings, animals and vegetation as a outcome of their mobility in aqueous ecosystem, toxicity and nonbiodegradability. This work aimed at the development of new adsorbent in the detoxification of heavy metals using Manilkara zapota tree wood and de oiled soya. The study completely focused on the characterization of the developed activation in the view of using it as a adsorbent. The characterization of activated carbon was effected SEM analysis, FTIR, XRD analysis and surface area determination. Both the activation carbon have showed a tremendous characterization in their employability as adsorbent in adsorption of heavy metals in aqueous solution. Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
1. Introduction Accelerated growth of human population and increasing technological innovation have spoiled the environment to a great level during the few years [1]. Unjustifiable utilization of natural resource and extreme use of toxic natured material might put in danger the very survival of life on this earth and evident environmental intervention intimidating the life maintain structure. The occurrence of components like toxic heavy metal ions or relentless organic pollutants might produce terrible effects on the ecosystems where they are released into. Heavy metals are normally stated to as those metals which have a specific density of more than 5 g/cm3 [2] which badly affect the environment and living organisms [3]. The release of domestic and industrial effluents and other man-made activities have arised in high levels of heavy metals accumulation in drinking water sources [4]. Amongst diverse metal ions, divalent lead and hexavalent chromium are most normally present in the environment and very harmful to human and ecosystem too. Therefore, it is requisite to treat metal infected wastewater before its set free into the environment. It initiates research at the core level to guard the environment from metal waste toxicity. As per USEPA (U.S. Environment Protection Agency) the divalent lead concentration must be below the level of 15 parts ⇑ Corresponding author. E-mail address: [email protected] (S. Sujatha).
per billion for drinking water and hexavalent chromium concentration 100 parts per billion for drinking water [4,5]. For wastewaters the concentration of both metals is 0.1 mg/l, given by both USEPA and Bureau of Indian Standards (BIS) [4,6]. Heavy metal elimination from industrial effluents can be done by conservative treatment techniques like chemical precipitation [7], coagulation, complexation, ion exchange [8], adsorption by activated carbon [Peters1985. Nevertheless, adsorption process is competent and eco-friendly technique particularly for the exclusion of heavy metal ions from aqueous solution. In this study, activated carbon were fabricated from citric acid treated Manilkara zapota tree wood and from de-oiled soya independently and their material characterization like presence of functional groups and surface morphology were evaluated with Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analysis to find the suitability to act as s adsorbent in the adsorption of divalent lead and hexavalent chromium.
1.1. Lead toxicity Lead is widely used in the industries similar to battery manufacturing, pigments, fuels, photographic materials, explosive manufacturing and printing. Spotlight to lead is highly inclined to health damages for children and adults as well [8,9]. Equally, calcium present in bone is replaced by lead.
https://doi.org/10.1016/j.matpr.2019.06.735 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
2
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1.2. Chromium toxicity Environmental pollution payable to chromium is most perceptible in leather manufacturing [10] electroplating [11], electronic manufacturing and other metal based operations. The carcinogenic and mutagenic character of hexavalent chromium [12,13] create ecological damage and health problems to mankind. 2. Materials and methods 2.1. Adsorbent Adsorbent is a solid substance that has a ability to adsorb another matter. Significant types of adsorbents in live out are silica gel, activated carbon, molecular sieve carbon, molecular sieve zeolites, activated alumina, and polymeric adsorbents. Many adsorbents are man-made (such as activated carbons), but a minimal adsorbents like zeolites, occur naturally. Every material has its own characteristics such as porosity, pore structure and nature of its adsorbing surfaces. 2.2. Adsorbate The matter which is being adsorbed on the surface of another matter is termed as adsorbate. Effluents such as heavy metals, dyes which have the ability to be adsorbed by the adsorbent are named as adsorbate. In common those matters which are to be abolished greatly from the atmosphere are coming under the category of adsorbate. 2.3. Activated carbon Activated is a porous, amorphous solid encircling of micro crystallites with a graphite lattice. Adsorption capacity is correlated to the surface morphology and chemical nature of the carbon surface in alliance with preparation conditions. So the present paper deeds to study the viability of using activated carbon developed from Manilkara zapota tree wood and de oiled soya. 2.4. Precursors used in the development of activated carbon Manilkara Zapota tree wood and de oiled soya were the two precursors used for the production of activated carbons.
the waste product which is received after the extraction of the oil is termed as de oiled soya. De oiled soya was collected from a private industry in Tamilnadu. 2.5. Preparation of activated carbon The present study intended to set up a new activated carbons developed from Manilkara zapota tree wood and de oiled soya independently. 2.5.1. Preparation of activated carbon of Manilkara zapota tree wood The preparation procedure involved the following stages a) Manilkara zapota tree wood was ground into small pieces and washed with distilled water to remove foreign materials. b) The materials obtained were heated in an oven at a temperature of 70° C for 4 to 5 h till it was completely dehydrated c) The dried ground wood was washed again with 0.1 N NAOH solutions thoroughly and stirred at 200 rpm for 60 min to remove the excess base from the wood. d) The resultant bio-mass was immersed in the citric acid for 5 h. Thereafter it was dried in oven for 3 h at a temperature of 105° c followed by burning process in a muffle furnace at 500° c for 3 h. e) The tree based carbon obtained was again kept in an oven at a temperature of 105° c for an hour for the accomplishment of carbon activation procedure. f) Manual crushing of the activated carbon was carried out to reduce the size of the carbon. g) The carbon that conceded in 150m sieve and hung in 90m sieve was stored in an airtight container. Manilkara zapota tree wood pieces were displayed in Figs. 1 and 2 indicated the activated carbon of it. 2.5.2. Preparation of activated carbon of de oiled soya The procedure concerned the following stages. 1. The development of the adsorbent was made by first grinding the de oiled soya into small pieces and washing with distilled water and drying in an oven till it was dehydrated.
2.4.1. Manilkara Zapota tree wood Manilkara Zapota tree across the world is well-known as the sapodilla tree, is a long-lived, evergreen tree native to southern mexico, central america and the caribbean. It produces a sweet, luscious fruit sapota. It is a drought-resistant and wind-resistant tree. Sapodilla can grow over 30 m (98 ft) tall with an average trunk diameter of 1.5 m (4.9 ft) and being a deep rooted and drought-resistant crop has been found to be an ideal plant for two tier cropping system with chilies as an intercrop in dry areas. India is the largest producer of sapota followed by Mexico, Guatemala and Venezuela. India has 162 thousand hectares of land under cultivation of sapota and produces about 1358 thousand tones of sapota per year. In Tamilnadu, it has become a very popular fruit crop in Dindigul, Coimbatore, Virudhunagar, Theni and Namakkal. 2.4.2. De oiled soya Another precursor, de oiled soya is derived from a bean called glycine max, commonly known as soya bean. It is a legume species native of East Asia which is widely grown for its bean which is edible in nature. Soya oil is prepared by crushing the soya bean and
Fig. 1. Zapota tree wood.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
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Fig. 4. Activated carbon of de oiled soya. Fig. 2. Activated carbon of manilkara zapota tree wood.
2. In order to oxidize the impurities the dried de oiled soya was then treated with hydrogen peroxide solution (30% w/v) at room temperature for about 24 h [14]. 3. The resultant material was washed with distilled water. the hydrogen-peroxide treated adsorbent was positioned in an oven at 100°c by which the moisture was removed. 4. Furthermore, it was kept in a muffle furnace at 350°c temperature for a time period of 3 h. 5. The obtained carbon was reduced in size by crushing the same. yet again it was set aside in a muffle furnace at 200°c for 1 h for activation process. 6. The carbon was subsequently sieved into two mesh sizes is 150m and 90-m sieves. 7. Carbon that was retained in the 90-m sieve and passing through the 150-m sieve was stored in an airtight container for further experiments.
(SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons ZEISS EVO-18 scanning electron microscopic instrument was employed in the present study to capture the SEM images of ACs of Manilkara Zapota and de oiled soya before and after adsorption.
2.7. Fourier transform infrared (FTIR) spectroscopic analysis
2.6. Scanning electron Microscopic (SEM) analysis
FTIR is a rapid, nondestructive, time saving method that can detect a range of functional groups in sample and used to characterize the functional groups responsible for heavy metal adsorption [16,17]. The functional groups responsible for adsorption of chromium (VI) and lead (II) metal ions of ACs of de oiled soya and Manilkara zapota tree wood were investigated by FTIR analysis. The frequency ranges are measured as wave numbers typically over the range 4000–400 cm 1. Infrared spectroscopic technique is conducted in an instrument called an infrared spectrometer (or spectrophotometer). Fourier transform infrared spectroscopy Perkin Elmer make – model spectrum RX1 (Range 4000–400 cm 1) was employed to obtain the FTIR spectrum of the adsorbents in the current study.
The SEM technique provides information on the association of metals in an adsorbent [15]. A Scanning Electron Microscope
2.8. X-Ray Fluorescence (XRF) Elemental analysis
De oiled soya was displayed in Figs. 3 and 4 revealed the activated carbon of it.
XRF analytical microscope determines the chemistry of a sample by measuring the emitted fluorescent X-ray from a sample. The sample is excited by a primary source to produce X-ray which is a secondary source from the sample. Presence of various elements in the activated carbons developed from Manilkara zapota and de oiled soya were determined by using XGT-2700 X-ray analytical microscope.
2.9. X-Ray Diffraction (XRD) Elemental analysis
Fig. 3. De oiled soya.
X-ray diffraction (XRD analysis or XRPD analysis) is a unique method in determination of crystallinity of a compound. The characteristic x-ray diffraction pattern generated in a typical XRD analysis provides a unique ‘‘fingerprint” of the crystals present in the sample. The adsorbents developed in this research were undergone analysis in X-ray X-Pert pro panalytical instrument.
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2.10. Brunauer-Emmett-Teller (BET) analysis Gas adsorption analyzer with Brunauer-Emmett-Teller (BET) method was exercised in the present study for the surface area determination where N2 gas was used as adsorbate. It serves as the measurement of the specific surface area of materials. 3. Results and discussion 3.1. Scanning Electron Microscopic (SEM) analysis Surface morphological images of AC of Manilkara zapota tree wood and de oiled soya were exhibited in Figs. 5 and 6. SEM images of both the ACs revealed the existence of irregular and porous surface which could facilitate the adsorption of metal ions on different pores of the adsorbent. A good deal of space was visible in both adsorbents which would be more beneficial for the adsorption process to occur on the surface of the carbon. Both the adsorbents had rough texture with heterogeneous surface and a variety of randomly distributed pore size which is a characteristic of a potential adsorbent. A rough surface and abundant pores would provide suitable diffusion passages for ions onto the carbons [18].
Fig. 6. SEM image of AC developed from de oiled soya.
3.2. Fourier Transform Infrared Spectroscopic analysis (FTIR) and Brunauer–Emmett–Teller (BET) surface area analysis From the Fig. 7 it could be clearly known that AC prepared from Manilkara zapota possessed a broad peak at 3433.06 cm 1 [21,19,20] could be allotted to AOH stretch from hydroxyl to phenolic groups. Similarly the peaks appeared at 2937.2 cm 1 and 1421.18 cm 1 were attributed to CAH stretching of aliphatic acids [19]. In this AC the peaks from 1299.46 cm 1 to 1046.03 cm 1 were endorsed to CAO stretching of alcohols [19,21]. Further the peak with wavelength 1115.08 cm 1 [22]possessed the functional group CAO stretching of carboxylic acid and alcohols in the adsorbent. Likewise the peaks located in between 926.07 cm 1 and 816.14 cm 1 were authorized to CAH aromatic rings [22]. It was observed from Fig. 8, that the FTIR spectrum of the AC prepared from de oiled soya was consisting of peak at 3339 cm 1 [19,20] could be attributed to AOH (hydroxyl) groups. The peaks 2870.49 cm 1 and 2926.49 cm 1 indicated the presence of CAH stretch of aliphatic [19] acids in AC. It further revealed peaks at 1651.14 cm 1 related to C@C [23] stretch alkenes. The Peak 1603.55 cm 1 referred to C@O (carbonyl group)stretch aromatic
Fig. 7. FTIR spectrum of AC developed from Manilkara zapota.
Fig. 8. FTIR spectrum of AC developed from de oiled soya.
Fig. 5. SEM image of AC developed from Manilkara zapota.
groups like primary and secondary amides [21,22]. The peaks 1113.06 cm 1 and 1161.17 cm 1 [22] exhibited the existence of CAO stretching of alcohols, and carboxylic acid in the adsorbent.
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Furthermore the peaks between 700.73 cm 1 and 753.80 cm 1 could be assigned to CAH aromatic rings [22,24]. The surface area was found to be 24.47 m2/g for de-oiled soya activated carbon and surface area was found to be 29.12 m2/g for Manilkara zapota tree wood based activated carbon. These surface areas had a good deal in favoring the adsorption process. 3.3. X-Ray Fluorescence (XRF) elemental analysis From Table 1 it was clear that seven heavy metals such as Si, K, Ca, Ti, Fe, Cu and O were found in activated carbon of Manilkara zapota. Among these, K, Ca and O were concentrated on 85.934% of weight. On the other hand seven heavy metals such as Si, K, Ca, Ti, Mn and Fe were found in activated carbon of de oiled soya. Among these, K and Ca were identified as key elements and they were concentrated on 83.17% of weight. The order of elements in activated carbon of Manilkara zapota is O > Ca > K > Si > Fe > Ti > Cu
Fig. 9. XRD spectrum of AC of Manilkara zapota.
The order of elements in activated carbon of de oiled soya is K > Ca > Si > Ti > Mn > Fe It was pragmatic from the Table 1 that activated carbon of Manilkara zapota had no manganese content but has high calcium ion content of 28.939% and several other metals. Whereas activated carbon of de oiled soya had low manganese content but had high potassium and calcium ions content of 55.43% and 27.74% respectively. Transition metals like Cu, Mn, Fe and Ti were present in the ACs which could be act as catalyst during adsorption process. 3.4. X-Ray Diffraction (XRD) analysis Fingerprint of the ACs were attributed to the peak intensities exhibited in the Figs. 9 and 10. This was by the distribution of atoms within the ACs lattice. In the spectrum very less number of peaks were observed which showed that the developed carbons were amorphous in nature. The peaks observed in XRD patterns 2h = 25°and 48° in both the carbon samples were due to the existence of Faujasite and Sodium Silicates [25] respectively. In addition to it AC of Manilkara zapota had peaks 2h = 29° and 31° were due to the presence of Zeolite and Mullite [25]. 4. Conclusion SEM analysis exposed the presence of irregular and porous surface which could smooth the progress of the adsorption of metal ions on different pores of the the developed activated carbon of Manailkara zapota and de oiled soya are. The FTIR spectrum
Fig. 10. XRD spectrum of AC of de oiled soya.
potrayed that the carbons have hydroxyl, carboxy and amine groups which have a greater affinity towards the heavy metal ion. Less number of peaks in XRD spectrum were observed which illustrated that the developed carbons were amorphous in nature. It could be concluded that the activated carbon produced from Manilkara zapota and from de oiled soya independently showed a tremendous charecterisation which can be better used as a adsorbent in adsorption process of detoxifying the heavy metal contaminated water.
Table 1 Elemental composition of activated carbons as revealed by XRF. Adsorbent elements
AC of Manilkara zapota % by weight
AC de oiled soya % by weight
Si K Ca Ti Fe Cu O Mn Total
7.464 27.791 28.939 2.987 3.133 0.482 29.204 – 100
9.77 55.43 27.74 1.11 5.36 – – 0.59 100
References [1] Indur M Goklany, ‘Have increases in population, affluence and technology worsened human and environmental well-being?, Electron J. Sustain. Dev. 1 (3) (2009) 3–28. [2] A.B. Duwiejuah, S.J. Cobbina, N. Bakobie, Review of eco-friendly biochar used in the removal of trace metals on aqueous phases, Int. J. Environ. Bioremed. Biodegr. 5 (2) (2017) 27–40. [3] Lars Jarup, Hazards of metal contamination, British. Medical Bulletin, The British council, vol. 68, 2003, pp. 167–182. [4] R. Vinodhini, M. Narayanan, Bioaccumulation of heavy metals in organs of fresh water fish Cyprinus carpio (common carp), Int. J. Environ. Sci. Technol. 5 (2) (2008) 179–182.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735
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[5] Ebtesam El-Bestawy, Majdah Abu Rass, Mervat Amin Abdel-Kawi, Removal of lead and oil hydrocarbon from oil refining-contaminated wastewater using Pseudomonas spp, J. Natl. Sci. Res. 3 (11) (2013) 112–124. [6] Sumeth Khaoya, Ura Pancharoen, Removal of lead (II) from battery industry wastewater by HFSLM, Int. J. Chem. Eng. Appl. 3 (2) (2012) 99–103. [7] M. Wiemann, K. Schirrmacher, D. Busselberg, Interference of lead with the calcium release activated calcium flux of osteoblast-like cells’, Calcif. Tissue Int. 65 (1999) 479–485. [8] Lovell Agwaramgbo, Nancy Magee, ShaKayla Nunez, Kayla Mitt, Biosorption and chemical precipitation of lead using biomaterials, molecular sieves, and chlorides, carbonates, and sulfate Na & Ca, J. Environ. Prot. 4 (2013) 1251– 1257. [9] Philip J. Landrigan, Clyde B. Schechter, Jeffrey M. Lipton, Marianne C. Fahs, Joel Schwartz, Environmental pollutants and disease in American children: estimates of morbidity, mortality, and costs for lead poisoning, asthma, cancer, and developmental disabilities, Environ. Health Perspect. 11 (7) (2002) 721–728. [10] Sadia R. Tariq, Munir H. Shah, N. Shaheen, A. Khalique, S. Manzoor, M. Jaffar, Multivariate analysis of trace metal levels in tannery effluent in relation to soil and water: a case study from Peshawar, Pakistan, J. Environ. Manage. 79 (2006) 20–29. [11] Siddiqa Tufail Mughal, Tahira Shafique, Tayyaba Aftab, Farzana Bashir, Treatment of electro plating effluen, J. Chem. Soc. Pakistan 30 (1) (2008) 29– 32. [12] Tor Norseth, The carcinogenicity of chromium, Environ. Health Perspect. 40 (1981) 121–130. [13] S. Sujatha, G. Venkatesan, R. Sivarethinamohan, Principal determinants of toxicity reduction by de-oiled soya using multivariate statistics: principal component analysis and multiple linear regression analysis, Appl. Ecol. Environ. Res. 15 (3) (2017) 1717–1737. [14] Alok Mittal, Damodar Jhare, Jyoti Mittal, Adsorption of hazardous dye Eosin Yellow from aqueous solution onto waste material De-Oiled Soya: isotherm, kinetics and bulk removal, J. Mol. Liq. 179 (2013) 133–140. [15] Young-Hoon Jo, Si-Hyun Do, Yoon-Seok Jang & Sung-Ho Kong, The removal of metal ions (Cu2+ and Zn2+) using waste-reclaimed adsorbent for plating
[16]
[17]
[18] [19]
[20]
[21]
[22]
[23]
[24]
[25]
wastewater treatment process, in: Proceedings of the World Congress on Engineering and Computer Science(WCECS 2010),San Francisco, USA, 2010. Florina Csernatoni, Carmen Socaciu, Raluca Maria Pop, Florinela Fetea, Florina Bunghez, Application of FT-IR spectroscopy for fingerprinting bioactive molecules in a nutraceutical PROMEN, comparatively with plant ingredients, J. Food Sci. Technol. 70 (1) (2013) 68–69. Sahira Joshi & Bhadra Prasad Pokharel, preparation and characterization of activated carbon from lapsi (Choerospondias axillaris) seed stone by chemical activation with potassium hydroxide, J. Inst. Eng. 9 (1) (2012) 79–88. Dongmei Jia, Changhai Li, Adsorption of Pb (II) from aqueous solutions using corn straw, Desalination Water Treat. (2014) 1–9. Sarifah Fauziah Syed Draman, Norzila Mohd, Nor Hafiza Izzati Wahab, Nurul Syahirah Zulkfli, Nor Fatin Adila Abu Bakar, Adsorption of lead (II) ions in aqueous solution using selected agro-waste, ARPN J. Eng. Appl. Sci. 10 (1) (2015) 297–300. Ting Wang, Weican Zhang, Lu. Xuemei, ‘Preparation Cu (II) adsorption characteristics of carboxymethyl cross-linked sewage sludge, Pol. J. Environ. Stud. 25 (2) (2016) 805–811. Ch. Suresh, Y. Harinath, B. Ramesh Naik, K. Seshaiah, Removal of Pb (II) from aqueous solution by critic acid modified Manilkara zapota leaves powder: equilibrium and kinetic studies, J. Chem. Pharmuetical Res. 7 (4) (2015) 1161– 1174. Parag A. Pednekar, Bhanu Raman, The FT-IR spectrometric studies of vibrational bands of Semecarpus anacardium Linn. F. leaf, stem powder and extracts, Asian J. Phamaceutical Clin. Res. 6 (1) (2013) 159–168. Macharia A. Njoki, Githua Mercy, Gathu Nyagah, Anthony Gachanja, Fourier transform infrared spectrophotometric analysis of functional groups found in Ricinus communis L. and Cucurbita maxima lam. roots, stems and leaves as heavy metal adsorbents, Int. J. Sci. Environ. Technol. 5 (3) (2016) 861–871. M.N. Younis, M.S. Saeed, S. Khan, M.U. Furqan, R.U. Khan, M. Saleem, Production and characterization of biodiesel from waste and vegetable oils, J. Qualityand Technol. Manage. V (1) (2009) 111–121. Z. Al-Qodah, R. Shawabkah, Production and characterization of granular activated carbon from activated sludge, Braz. J. Chem. Eng. 26 (1) (2009) 127– 136.
Please cite this article as: S. Sujatha and R. Sivarethinamohan, Investigation of detoxification nature of activated carbons developed from Manilkara zapota and de oiled soya, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.735